Worldbin: Space. It’s Big.

One of the things that people don’t realise in sci-fi, is how big the universe is. It is 4.2 light-years to Proxima Centauri, our nearest solar system. That means that anything you send there will get there at least 4.2 years later. More so, for slower things, like ships. And at least 8.4 years for the return journey. Therefore, even if we could colonise other Solar Systems, they would really be on thier own.

So, just to stay intra-solar, which is probably the best bet to start off with – colonise the planets, make a Dyson Sphere and Solar Sails, create a post scarcity society – the usual stuff in SF. But even that is quite far away. Say, for example, that someone on Mercury wanted to talk to someone on Neptune, they would have a delay of 4 hours and 12 minutes. And if we could go at a 0.01c (which is still pretty quick – 10 million km/hour), it would take them 17 days to get there.

Therefore, if extra-solar civs are like islands in an ocean, with little or no contact, then intra-solar civs are like city-states – close enough to interact, trade, and talk, but far enough away to be independant.

If you do manage to get faster-than-light travel (which is possible, it just needs an implausible amount of energy), then you still don’t get around the communication problem. You would have to use physical messengers which would transmit the data. A more useful version would be to create a wormhole. Then the communications would be almost instantaneous, and bulk matter transmission would also be available. However, once you had created the wormhole then you would have to move it to your destination at realtivistic speeds, and if your only one breaks down, they you would have to wait for a replacement. I’m not even going to speculate what would happen if you moved a wormhole through a wormhole.

And as for people who imagine an entire galactic civilisation, and the communication system that that would entail, the distance from the Sun to the centre of the Milky Way is 26,400±1,600 light years. Unless you lived for an exceptionally long time, and/or your metabolic rate made rocks look like mayflies, then carrying out a communication over that distance is not worth thinking about. And don’t even get me started on all that pan-galactic stuff…..